OTAGO INSTITUTE.

Otago Witness, Issue 1243, 25 September 1875, Page 7

OTAGO INSTITUTE.

The regular meeting of the Otago Institute took place on the 14th inst, when abont 30 members, and several ladies were present. The President (Mr J. S. Webb) occupied the ohair.

THE HABITS OF THE THAP-DOOIt SPIDER.

In laving before his hearers his observations regarding the habits of the trap-door spider, Mr Gillies promised that their wonder and surprise would only be equalled by their desire to know more and more of the marvellous structures of this insect. As compared with similar works accomplished by human agency, the underground excavations of the trap-door spider were truly wonderful. Driven some 15 inches into the ground, whether through compact clay or loose sand soil, the shaft which it constructs is lined throughout with a tough silken coating, and the most perfect ventilation and drainage are provided for. At the mouth of the shaft is a trap-door, constructed of the same material as the lining, and provided with a hinge ingeniously fashioned. Externally this door so resembles the surrounding vegetation as to defy detection. The name given these spiders in no way implies that they are given to entrapping or snaring smaller insects, as many of the spiders do, but has been suggested on account of the wonderful door which covers the entrance to their nests being the peculiar work of this species. Before proceeding to set forth in detail the results of hia observations during the last two years, Mr Gillies desired it to be understood that he laid no claim to the position of a cabinet naturalist, whoso functions in the domain of natural history were those of classifying and describing in the atudy. He had prosecuted the work he had taken in hand solely as a field naturalist, whose place it waa to collect specimens of natural history, to observe and record the habits of animals and plants, and to note the localities in which they are found. A description of the Otago trap-door spider would shortly be obtained from home, as, through the kindness of Capt. Hutton, several specimens had bjen forwarded to the Rev. Pickard Cambridge, the greatest authority on the subject in England. Mr Gilhes then explained how it was that big attention was first directed to theae spiders. "My first discovery of their existence in Otago was purely accidental. Rather more than two years ago, I was riding slowly through an English grass paddock in our Awamoko Estate, near Oamaru, with our manager. On a bare patch of ground, my eye accidentally rested upon a very large spider. Attracted by its size, I kept steadily looking at % when suddenly, as if by magic, it diafypujMiZ totally, U my MtoiMwAt; I

exclaimed: 'Well, Little, did you ever hear of a spider that could fly, for' I could take my oath that I saw an immense spider down on that bare patch just now, and it disappeared in a moment, and if it did not ffy away, it can't have gone anywhere else.' So, I got off my horse and handed him the reins, so as to carefully examine the ground, which was very diy aud dusty. My suspicions that the spider had rolled itself up in the dust were soon confirmed by observing that the earth was a little raised or bulged up at one part, and so I took my knife to turn him out of his dirt heap. Judge of my surprise and delight when, no sooner had I applied the point of my knife, when up sprung a beautiful trap-door, revealing a large hole going right down into the earth, lined with beautiful white silk that shone in the sun and that covered over the inside of the door, and formed a clever and remarkably good hinge. I had no doubt now where the spider had gone, but having no tools with _ us- we could not dig it out. I examined this strange novelty some time, lifting up the wonderful door, and admiring the exactness with which it fitted, the perfect mobility of the hinge, the spring which immediately shut down on slipping from the knife, and the marvellous adaptation _of the outside of the lid to the existing conditions surrounding it. It was literally peppered on the outside with loose soil, exactly the same as that around, so as to defy detection by anyone unacquainted with the way of finding such nests. In fact, although I had carefully marked several things near by, so as to find it again, when I returned with a spade I could not find it, aud never afterwards came upon this particular nest. I cannot express to you my surprise and delight in thus being brought face to face with one of the most wonderful and difficult problems in Nature. You must bear in mind that although I had a general smattering of Zoological knowledge, I knew nothing of the trap-door spiders, and in looking up any books I had, I found the matter referred to in such a matter-of-course, 'wellknown fact,' sort of style, that I hastily concluded that my ignorance was the only wonderful thing about the matter, and that, no doubt, everything that could be known about them, was known by naturalists, and, consequently, it would be mere waste of time systematically to observe them. Some time after this, our worthy Hon. Secretary, Captain Hutton. came to reside amongst us, and one night I referred to the mattei- in an off-hand incidental sort of way, being half afraid to reveal my ignorance on such a trifling matter. To my delight, he was immediately interested, expressed his Rurprise, as it was the first time they had been found in New Zealand, told me they were very rare all over the world, and very little Avas known about them, put me in the way of getting what information there was, and begged me to pursue my investigations. This shows the advantage of having a gentleman like Captain Hutton as^ an authority on such matters. One works with so much better heart, when he knows he is not pursuing a track, and spending valuable time over a matter that has been gone over by some one else, perhaps with better opportunities, and to much better purpose. I gladly acknowledged my indebtedness to Captain Hutton for the kind help and encouragement he has given me, for without the incentive of his generous encouragement to me, as a beginner in the practical study of natural history, I am sure that I should not have devoted the time and thought to it that I have. I must also add that the study of those animals has opened up to myself, personally, an extended view of many things in nature, and supplied me with a source of pleasure and instruction, far beyond the value of the time and labour bestowed on it. And let no one say this is a trivial matter —only the determination of the habits, &c, of a class of spiders. As I take it, every genuine fact found out about this wonderful world, in which God has placed us, is a new leaf added to his great Record of Truth— a record, the full import and intent of which we know little about as yet, and as I shall show, if I have time, at the end of thi3 paper, there are thoughts suggested, and questions raised, by even those tiny insects, which are as farreaching aa the circle of the world, and in the ultimate and correct solution of which, every item of truth, however insignificant, will ultimately bear its part, and without the knowledge of which any solution would be insufficient. Since the time of my understanding from Captain Hulton that the study of these spiders would be useful, I have taken every opportunity of my being in the Oamaru district to observe and record what I saw of them ; and in the months of October and November last year, being detained there through illness, I had some weeks of leisure to pursue my investigations, the results of which I now propose to lay before you."

The sub-order of Araneidea to which the trap-door spiders belong was known as the Territelariae, and so far as he (Mr Gillies) could ascertain, the specimens which he was enabled to produce belonged to the same species, although there were varieties amongst them. These he proceeded to describe. He also pointed at considerable length to the peculiarities of the nests, several examples of which were on the table. In referring to the habits of these animals, he explained that, although they lived in colonies, it was not to be inferred that they were sociably inclined So far from this being the case, he had on only one occasion discovered two spiders in one nest, and this was a nest in which there were two galleries. So pugnacious are they that, upon two of them being placed in a matchbox together for a night, it was found in the morning that the one had eaten the other. He gave some instances, too, of their wonderful knowledge of mechanical resistance, and how to employ it in defence of their "hearths and homes." Their attachment to their nests, also; is so great that they prefer to starve in them rather than abandon them. After some remarks upon the food of the spiders, and upon the natural enemies they had to encounter, Mr Gillies referred to their geographical distribution. In Otago, they are to be found from the Waitaki as far south as Shag Valley, and specimens have been obtained in Wellington; while in Auckland, their nests have been found in the scoria walls. Mr Gillies concluded his interesting paper by Baying :— " I rather incline to the opinion that this species will be found to be limited by the character of the soil and by climate, more than by food, especially as the very few places throughout the world where they have been found, all coincide (so far as I know) in having a light soil, and warm, dry, climate. Should this prove to be the case, it will open up a wide and interesting field for speculation as to the causes which have led to their distribution to such remote corners of the globe, and to their limitation to such small and confined areas. Have they all spread from one centre of creation, or have different types been originated in separate areas of development? Whichever it is, we are pretty sure of this, either that enormous periods of time must have elapsed since the first parent stock migrated east and west to such extremes of the world as Jamaica and New Zealand (especially when we consider the very different locomotive powers of the species, and its extreme reluctance to leave its native home), or, on the other hand, that some common power hati been at work controlling and direct|n; fcjie development of guch, raayyell«up}v

intelligeßg and skilfully artistic creatures, in such remote and opposite parts of the globe." The PbSsident complimented Mr Gillies upon his paper, saying it was of a class which the members were extremely anxious to &cc a great many of. He thought it very probable that, when these practical observations were made known, there would be a good deal more interest displayed in the remarkable habits of the trap-door spider. Mr A. Bathgate related his experience in connection with some trap-door spiders about five or six years ago at Cromwell. He had no doubt that specimens could be found in the inland plains— the Maniatoto, for instance. Professor Mac(Uu:g or said that part of Mr Gillies's^ paper which interested him most was that which likened themselves to the insects. People were in the habit of looking at the universe as a three-storey house built for their convenience. Mr Gillies had given them curious and beautiful instances of the insects, showing that they had reason to move themselves. The paper had impressed him greatly. None of the Creator's creatures, however small, were quite below consideration. Captain Hutton remarked that Mr Gillies said the spider had no enemies, but he had evidently forgotten the weka, which liked spiders very much. These woodhens were all over the country. He (Captain Hutton) thought the pains tbe spider took to hide his nest was on account of the woodhen. He concluded by humorously referring to a paper he had received from a well-known analyst at CambridgeTwo other members expressed their opinions on the habits of the trap- doer spicier, and referred to an interesting article on the subject in a late number of the Contemporary Review. ( Mr Giixies, in reply, did not agree with Captain Hutton's theory regarding 1 the weka. Mr John Reid, of Elder&lie, had seen black beetles going into the bpidei's holes, and they might be enemies to the spider. He (Mr Gillies) thought the case before them, in these nests, were better samples of mimicry than anything he had seen in books of Natural History. The President announced that the next meeting would take place a fortnight hence, and hoped that papers would be read fortnightly till the end of the session.